Moisture

[Ken Prater]

I have a stack of Maple boards that were sawed in early March of this year. They have been air drying in my barn/garage. When can I expect them to be dry enough? Thanks for any input...

[John TenEyck]

You don't say so I'll assume they are 4/4 boards and they have been stickered properly with good airflow through the stack. If so, they will get down to an EMC equivalent to whatever the avg. humidity is in your barn. By this Fall they will probably be as dry as they are going to get (maybe in the range of 14 - 16%), unless you heat that space in the Winter. If so, they will dry further, again in equilibrium to whatever the avg. humidity is. If you want to get the wood down to 8% moisture, the avg. humidity has to be 45% for several weeks. The easiest way to know what's going on with your wood is to get a moisture meter and a humidity gage. Good luck.

[Scott T Smith]

If they are 4/4 and have any air flow to speak of through the stacks, they will already be at EMC.

If they are 8/4, you might have another month or two to go.

[Cody Colston]

It takes about 150 - 180 days of good drying weather to air-dry 4/4 wood below 20% MC. To get it to EMC could take upwards of a year, depending on conditions. Heat, air movement and relative humidity are the factors that determine drying rate.

The heat factor has pretty much been taken care of by Mother Nature this summer. That leaves RH and air movement. Hopefully you stickered the wood (or it will be stained probably beyond use) when it was stacked. Air movement could be less than optimum since it's in a barn/garage unless you provided some via fans. Maple, being a light-colored wood, benefits from fairly rapid drying as long as the safe drying rate is not exceeded. (Hard Maple is 6.5% per day and Soft Maple is 13% per day)

Also, you will need to dry it beyond air-dry EMC before using it for indoor projects, no matter how long it has been stacked. The wood will not air dry below about 12% and you need it to be at 7% - 8% for a modern, air-conditioned/heated home.

[Ken Prater]

Thanks John, Scott, Cody, I knew I should have mentioned how thick they are but I'm still learning how the numbers 4/4,8/4 etc, mean. I guess they are 4/4 (a bit more than one inch thick). It is a stack about 4'wx3'hx12'l and they were sticked and banded by the mill. I was advised to put a fan on them for air movement which I did for a few weeks. The bands are loose now from shrinkage and the ends have not split at all. From monitoring the posts on here I get the impression that a moisture meter is expensive so tha option is out. Tjhanks a lot for the info guys....guess I'll wait a couple of months before trying to use them...

[Frank Drew]

Ken

I like using air-dried lumber, but for the purposes of furniture making I take a longer is better approach; I don't have any rigorous scientific testing to back this up, but my feeling is that wood continues to "relax" for a number of years past when it reaches equilibrium moisture content.

[John TenEyck]

I bought a used mini-Ligno moisture meter for around $50 on E-bay. Others have had good luck with one Lowe's recently was selling for something like $15. High end meters are expensive, but you don't need an expensive one to get relatively good measurements. Any moisture meter is better than none. And as a couple of us noted, your wood will never get down to 6 - 8% moisture no matter how long it's stacked in your barn. It would in Arizona, but not in Ohio. You will have to put it someplace where the humidity is 45% to dry it enough to then use it for furniture.